Ester synthesis

Abstract

The present invention relates to a process for preparing esters from fatty alcohols, in which fatty alcohols and fatty acids are reacted in the presence of an enzyme at a temperature in the range of 30 to 50° C., the water which forms is removed and the reaction is completed under reduced pressure at a temperature of 50 to 80° C.

The invention claimed is: 
     
       1. A process for preparing esters from fatty alcohols and fatty acids comprising the steps:
 reaction of fatty alcohols of the formula R 1 —OH, where R 1  is an aliphatic linear or branched hydrocarbon group having 6 to 22 carbon atoms, and fatty acids of the formula R 2 —COOH, where R 2  is an aliphatic linear or branched hydrocarbon group having 6 to 22 carbon atoms, in the presence of a lipase at a temperature in the range of 30 to 50° C. without water removal, until the reaction equilibrium is achieved; 
 removal of the water formed during the reaction after the reaction equilibrium is achieved; and 
 completion of the reaction under reduced pressure at a temperature in the range of 50 to 80° C. 
 wherein the lipase is used in an immobilized form. 
 
     
     
       2. The process according to  claim 1 , wherein the completion of the reaction is carried out in a stripping gas atmosphere. 
     
     
       3. The process according to  claim 2 , wherein the stripping gas comprises nitrogen, air, carbon dioxide, or argon. 
     
     
       4. The process according to  claim 1 , wherein a pressure of 100 to 10 000 Pa is applied during the completion of the reaction. 
     
     
       5. The process according to  claim 4 , wherein a pressure of 1500 to 4500 Pa is applied during the completion of the reaction. 
     
     
       6. The process according to  claim 1 , wherein the reaction is carried out at a temperature in the range of 35 to 45° C. 
     
     
       7. The process according to  claim 1 , wherein the completion of the reaction is carried out at a temperature in the range of 55 to 65° C. 
     
     
       8. The process according to  claim 1 , wherein the immobilized lipase is used in an amount of 0.5 to 5.0% by weight. 
     
     
       9. The process according to  claim 1 , wherein the fatty alcohols used are those whose linear or branched alkyl or alkenyl group has 8 to 18 carbon atoms. 
     
     
       10. The process according to  claim 1 , wherein the fatty acids used are those whose linear or branched alkyl or alkenyl group has 8 to 18 carbon atoms. 
     
     
       11. The process according to  claim 1 , wherein the ester preparation is carried out in a one-pot process. 
     
     
       12. The process according to  claim 1  further comprising steps of purification and preservation. 
     
     
       13. The process according to  claim 12 , wherein a forerun distillation, a product distillation for improving color, a deodorization for optimizing odor, and/or an addition of antioxidants are carried out. 
     
     
       14. The process according to  claim 1 , wherein the reaction to equilibrium step is conducted in the absence of reduced pressure. 
     
     
       15. The process according to  claim 1 , wherein the reaction to equilibrium step is conducted with mechanical agitation. 
     
     
       16. The process according to  claim 1 , wherein the removal of the water step is conducted by decanting without mechanical agitation. 
     
     
       17. The process according to  claim 1 , wherein the lipase is  Candida antarctica  lipase B.